Method of detinning.



H. BRANDENBURG.

METHOD OF DETINNING.

APPLICATION FILED 001.5, 1911.

1,012,51 1 Patentd Dec. 19, 1911.

- Inventor witnesses k n-W 6 18 11112112 OFFIQE.

HEINRICH BRAND IENBURG, 0F KEMPEI V--ON-THE-RHINE, GERMANY.

METHOD or DETINNING.

To all whom it may concern;

Be it known that I, HEINRICH BRANDEN- BU'RG, a subject of the GermanEmperor, and residing at Kempen-on-the-Rhine, Germany, have inventedcertain new and useful Improvements in Methods of Detinning, of whichthe following 'is a specification.

- My invention relates to methods for detinning metals covered wholly orin part by tin, and more particularly to methods for detinning scraps orother waste material carrying more or less tin.

More particularly stated, my invention relates to removal of the tin byaid of a suitable solvent capable of acting u on the tin, and especiallywhen the tin is oxidized. For this purpose the solvent may be either analkali or an acid.

I have made the discovery that when material to be treated is submergedin a solvent for tin, and is then exposed to the air and afterward againsubmerged in the solvent and again exposed to air, the success of thedetinning operation hinges largely upon the time intervals during whichthe material is submerged and exposed to atmospheric action. If thematerial, after being submerged in the solvent, is exposed for too longa time to atmospheric action, the sol-. vent upon its surface dries up,and if the submersion of the material be continued too long otherdifiiculties are likely to arise. When the material becomes too dry, andis afterward submerged in the solvent, the action of the liquid isrendered unduly slow.

My invention comprehends the alternate treatment of the material, firstby submerging it in a solvent and then lifting it out of the solvent, soas to expose it to the action of the air, in orderto promote oxidation,the submersion and the exposure to atmospheric air being properly timed,or in other words being continued for precise periods 'of time.

My invention also comprehends that the material to be operated upon ismoved vertically upward and downward, and that two quantities of thematerial are balanced against each other, so that when one quantity ofmaterial is being submerged the other quantity is raised and therebyexposed to atmospheric action.

For the purpose of handling the material appropriate holders may beemployed, but this is not in all instances necessary, as the materialmay be placed in' the form of packets or bales, if desired. It isdesirable that Specification of Letters Patent.

Application flied October 5, 1911.

Patented Dec. 19, 1911. Serial No. 653,018.

large holders be used, however, in instances where the material to bedetinned is made up of large masses of tinned iron and when the questionof cost of handling becomes an important factor. When the masses ofmaterial to be treated are raised out of the solvent they are freetocool rapidly, and the atmospheric air present can readily circulatethrough the masses.

No special form of apparatus is essential to the practice of myinvention, but for the sake of clearness and simplicity I show, by wayof example, two forms of apparatus which may be used in carrying out mymethod.

- Reference is made to the accompanying drawing forming a part of thisspecification, and in which like letters indicate like parts.

Figure l is a section showin one apparatus. Fig. 2 is a plan view of thesame. Fig. 3 is a detail showing an elevation of one of the holders.Fig. 4 is a section somewhat similar to Fig. 1, but showing a slightlydifferent form of the apparatus.

Referring to the structure shown in Figs.

1 and 2 there are two tanks A A for holding the solvent. The material tobe detinned is mounted in holders B, which are suspended from a beam C,the latter being fulcrumed at the point E. At D D are two tanks whichhold a liquid for washing the mate rials after their treatment in thetank D, and in the atmosphere. By tipping the beam G, the material canfirst be submerged in the solvent, and then raised into the air and thusexposed to the oxidizing influence of the latter, after which it may beagain submerged. The submersion and exposure of the different quantitiesof the materials to be treated are accurately timed. After the materialhas been thus thoroughly treated the beam C is turned horizontally andthe masses of material are washed by dipping each of the masses one ormore times in the washing liquid contained-within the tanks D D, thisbeing done most readily by merely tipping the beam C as before. Intreating the masses of material by alternately submerging them in thesolvent and lifting them into the air, a minimum of work is requiredbecause of the fact that the two masses balance each other upon the beamC. Moreover this arrangement of the various parts enables the time ofsubmersion to coincide with the time of exposure to the atmosphereprovided, of course, that care be exterials.

ercised in tipping the beam 0 at the right moment. Each time a mass ofmaterial is raised from the solvent and thus exposed to atmosphericaction there is more or less oxidizing accomplished by the air, and whenthis is done, if the material be again lowered and thus immersed in thesolvent, the tin is removed with great facility;

In the form shown in Fig. 4 I use a chain F engagin the pulleys G, andupon the ends of the cham I mount holders B for the ma- The tanks A Acontain thesolvent. Each holder is provided with an inner chamber E, aswill be understood from Fig. 3, in order to facilitate the access of theair to the charge of material.

I claim:

1. The process of detinning tin scraps which consists in maintaining twomasses of tin scraps in counterbalanced relation and alternatelysubjecting one of said masses to the action of a solvent for tin, and tothe action of air, and simultaneously subjecting for tin.

2. The method herein described of detinbalancing against each other twomasses of the material to be detinned, next simultaneously raisingonemass into the air and lowering the other mass into a solvent for tin,then simultaneously lowering into a solvent. for tin the mass firstraised and raising into the air the mass first lowered, so as to exposeto the oxidation of the atmosphere the tin carried by said mass firstlowered, and repeating the foregoing steps until substantially all ofthe tin carried by both masses is removed.

In testimony whereof, I aifix my signature in the presence of twowitnesses. I

HEINRICH BRANDENBURG. Witnesses:

RUDOLPH FRICKE,

FRIEDRIC O'r'ro WITTMAR.

ning waste tinned iron, which consists in

